Generic gas generators according to the present invention are described, for instance, in the DE 20 2004 001 017 U1 and are used e.g. in vehicle occupant restraint systems for inflation of airbags or activation of seat belt tensioners. They are preferably employed as driver-side generators and often are in the shape of a toroid. If a sensor detects presence of unusual acceleration values or a crash, a propellant is ignited in the gas generator releasing a pressurized gas. Due to the pressure of the released gas a gas flow is directed outwardly through outflow openings provided in the housing and is directed, for instance, into an air bag which inflates. So as to prevent undesired discharge of the particles produced during combustion, a filter is installed inside the gas generator between the combustion chamber where the propellant is ignited and the outflow openings of the housing. The filter prevents the aforesaid discharge through the outflow openings and simultaneously serves as heat sink.